Ventilation fan and ventilation system

ABSTRACT

A ventilation fan includes a body unit, which has a fan disposed in a body case and a fan controller operable to control an air volume of the fan. The ventilation fan also includes a sensor module having an indoor environment detecting sensor and a module controller operable to control a detecting operation of the indoor environment detecting sensor. The body unit has a module mount on which the sensor module is mounted and another sensor module can be mounted in place of the sensor module. The module mount is connected to the fan controller. The module controller outputs detection information obtained based on a detection result of the indoor environment detecting sensor to the fan controller, which in turn controls the air volume of the fan based on the detection information inputted thereto.

This application is a continuation of U.S. patent application Ser. No.14/383,151, filed Sep. 5, 2014, which is a U.S. National PhaseApplication of PCT International Application PCT/JP2013/001544, filedMar. 8, 2013, and claims priority to Japanese Patent ApplicationJP2012-052681, filed Mar. 9, 2012, Japanese Patent ApplicationJP2012-211828, filed Sep. 26, 2012, Japanese Patent ApplicationJP2012-260667, filed Nov. 29, 2012 and Japanese Patent ApplicationJP2012-205280, filed Sep. 19, 2012, the contents of which areIncorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a ventilation fan installed on aceiling.

BACKGROUND ART

A conventional ventilation fan of this kind includes a body case havingan indoor air suction opening defined in a lower wall thereof and anindoor air discharge opening defined in a side wall or upper wallthereof, a fan mounted in the body case, and a controller forcontrolling the operation of the fan. Further, for example, a human bodydetecting sensor is mounted as a sensor for detecting an indoorenvironment and connected to the controller. If the presence of a humanbody is detected by the human body detecting sensor, the controllercontrols the fan to drive it or increase the air volume (see, forexample, Patent Document 1 or 2).

PATENT DOCUMENTS

-   -   Patent Document 1: JP 6-300341 A    -   Patent Document 2: JP 2010-117111 A

SUMMARY OF THE INVENTION

However, as such a sensor for detecting the indoor environment, thereare various sensors such as, for example, a temperature sensor, ahumidity sensor, an illuminance sensor and the like in addition to thehuman body detecting sensor. There are also a great number ofenvironments, in which a ventilation fan is installed, such as, forexample, individual houses, individual offices and the like. For thisreason, many kinds of ventilation fans are required depending on thekind of sensor to be installed thereon and installation environments,thus resulting in an increase in production cost, management cost or thelike. Also, there are times when the kind of sensor must be changedafter a ventilation fan has been installed. In this case, the wholeventilation fan must be replaced.

The present invention has been developed to solve the above-describedconventional problems and is intended to provide a ventilation fan and aventilation system capable of reducing the production cost or managementcost.

A ventilation fan embodying the present invention includes a body unitthat includes a body case having an indoor air suction opening and anindoor air discharge opening both defined therein, a fan disposed in thebody case, and a fan controller operable to control an air volume of thefan. The ventilation fan also includes a sensor module having an indoorenvironment detecting sensor and a module controller operable to controla detecting operation of the indoor environment detecting sensor. Thebody unit also includes a module mount on which the sensor module ismounted and another sensor module can be mounted in place of the sensormodule, the module mount being connected to the fan controller. Themodule controller outputs detection information obtained based on adetection result of the indoor environment detecting sensor to the fancontroller, which in turn controls the air volume of the fan based onthe detection information inputted thereto.

A ventilation system embodying the present invention holds a ventilationair volume constant in a building and includes at least two ventilationfans of the above-described configuration installed in the samebuilding. Each ventilation fan includes an information transmittingportion operable to transmit its own air volume information determinedbased on detection information inputted from a sensor module mountedthereon to other ventilation fans, an information receiving portionoperable to receive information from the other ventilation fans, and anair volume decision means operable to compare a total air volume of theair volume information of its own fan and the air volume information ofthe other ventilation fans received by the information receiving portionwith a total ventilation air volume information in the building set inadvance to determine the air volume of its own fan so as to maintain thetotal ventilation air volume.

Effects of the Invention

The ventilation fan and the ventilation system according to the presentinvention can reduce the production cost or management cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cutaway perspective view of a ventilation fanaccording to a first embodiment of the present invention, showing anexample of installation thereof.

FIG. 2 is an exploded perspective view of the ventilation fan accordingto the first embodiment.

FIG. 3 is a control block diagram of the ventilation fan according tothe first embodiment.

FIG. 4 is an operation flowchart of the ventilation fan according to thefirst embodiment.

FIG. 5 is a partially cutaway perspective view of a ventilation fanaccording to a second embodiment of the present invention, showing anexample of installation thereof.

FIG. 6 is an exploded perspective view of the ventilation fan accordingto the second embodiment.

FIG. 7 is another exploded perspective view of the ventilation fanaccording to the second embodiment.

FIG. 8 is a control block diagram of the ventilation fan according tothe second embodiment.

FIG. 9 is a perspective view showing another example of a decorativeboard of the ventilation fan according to the second embodiment.

FIG. 10 is a perspective view showing a further example of thedecorative board of the ventilation fan according to the secondembodiment.

FIG. 11 is a perspective view of a remote controller of the ventilationfan according to the second embodiment.

FIG. 12 is another perspective view of the remote controller of theventilation fan according to the second embodiment with a lid opened.

FIG. 13 is an operation flowchart of the ventilation fan according tothe second embodiment.

FIG. 14 is another operation flowchart of the ventilation fan accordingto the second embodiment.

FIG. 15 is a partially cutaway perspective view of a ventilation fanaccording to a third embodiment of the present invention, showing anexample of installation thereof.

FIG. 16 is an exploded perspective view showing a configuration of theventilation fan according to the third embodiment.

FIG. 17 is a schematic block diagram showing the configuration of theventilation fan according to the third embodiment.

FIG. 18 is a partially cutaway perspective view of a ventilation fanaccording to a fourth embodiment of the present invention, showing anexample of installation thereof.

FIG. 19 is an exploded perspective view showing a configuration of theventilation fan according to the fourth embodiment.

FIG. 20 is a schematic block diagram showing the configuration of theventilation fan according to the fourth embodiment.

FIG. 21 is a configuration diagram showing a positional relationship inthe configuration of the ventilation fan according to the fourthembodiment.

FIG. 22 is a partially cutaway perspective view of a ventilation fanmounted in a ventilation system according to a fifth embodiment of thepresent invention, showing an example of installation thereof.

FIG. 23 is an exploded perspective view of the ventilation fan accordingto the fifth embodiment.

FIG. 24 is a view showing a floor area setting section provided on theventilation fan according to the fifth embodiment ((a) being an externalview and (b) being a correlation diagram between a floor area and an airvolume).

FIG. 25 is a control block diagram of the ventilation system accordingto the fifth embodiment.

FIG. 26 is a control flowchart of the ventilation system according tothe fifth embodiment.

FIG. 27 is an exploded perspective view of a ventilation fan mounted ina ventilation system according to a sixth embodiment of the presentinvention.

FIG. 28 is a control block diagram of the ventilation system accordingto the sixth embodiment.

FIG. 29 is a control flowchart of the ventilation system according tothe sixth embodiment.

FIG. 30 is a control block diagram of a ventilation system according toa modified form of the sixth embodiment.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

A ventilation fan according to the first invention comprises: a bodyunit including; a body case having an indoor air suction opening and anindoor air discharge opening both defined therein; a fan disposed in thebody case; and a fan controller operable to control an air volume of thefan; a sensor module including; an indoor environment detecting sensor;and a module controller operable to control a detecting operation of theindoor environment detecting sensor; wherein the body unit has a modulemount on which the sensor module is mounted and another sensor modulecan be mounted in place of the sensor module, and the module mount isconnected to the fan controller, and the module controller outputsdetection information obtained based on a detection result of the indoorenvironment detecting sensor to the fan controller, which controls theair volume of the fan based on the detection information inputtedthereto.

This configuration can separate the body unit and the sensor module fromeach other to allow the body unit to have a common specification. Also,a sensor module having an indoor environment detecting sensor requireddepending on an indoor environment can be mounted on the body unit so asto be replaced with another sensor module. Accordingly, in theventilation fan equipped with the indoor environment detecting sensor,the production or management cost can be reduced.

In the ventilation fan according to the first invention, the secondinvention is characterized in that the module controller outputsidentification information of the indoor environment detecting sensor tothe fan controller, which controls the air volume of the fan based onthe identification information and the detection information inputtedthereto.

This configuration allows the fan controller to identify the kind ofsensor module mounted on the body unit, thus making it possible to allowthe fan controller to perform a fan control depending on the mountedsensor module.

In the ventilation fan according to the first or second invention, thethird invention is characterized in that a plurality of sensor modulescan be simultaneously mounted on the module mount and the fan controllerhas an arithmetic section to calculate the air volume of the fan basedon different detection information inputted from the plurality of sensormodules using an algorism set in advance. This configuration allows thefan controller to realize a fan control based on the informationinputted from the plurality of sensor modules. Also, a fan controlassociated with the features of the indoor environment detecting sensorcan be realized, for example, by weighting the inputted informationdepending on the kind of sensor module.

In the ventilation fan according to any one of the first through thirdinventions, the fourth invention is characterized in that the modulecontroller determines air volume information of the fan based on a kindor the detection result of the indoor environment detecting sensor andoutputs the air volume information determined as the detectioninformation to the fan controller. The module controller determines theair volume information of the fan and outputs it to the fan controllerof the body unit, thereby making it possible to commonly and simplyconfigure a fan controller specification for various kinds of indoorenvironment detecting sensors.

In the ventilation fan according to any one of the first through fourthinventions, the fifth invention is characterized in that a connectingportion of the sensor module to be connected to the module mount has acommon shape with a connecting portion of another sensor module. By thisconfiguration, the sensor module can be easily replaced with anothersensor module.

In the ventilation fan according to any one of the first through fifthinventions, the sixth invention is characterized in that the sensormodule comprises at least one of a human body detecting sensor, atemperature sensor, a humidity sensor, an illumination sensor, a carbonmonoxide sensor and a carbon dioxide sensor as the indoor environmentdetecting sensor, thereby making it possible to provide a ventilationfan having a variety of functions.

A ventilation system according to the seventh invention operable to holda ventilation air volume constant in a building comprises: at least twoventilation fans according to any one of the first through sixthinventions installed in the same building; and each ventilation fancomprising; an information transmitting portion operable to transmit itsown air volume information determined based on detection informationinputted from a sensor module mounted thereon to other ventilation fans;an information receiving portion operable to receive information fromthe other ventilation fans; and an air volume decision means operable tocompare a total air volume of the air volume information of its own fanand the air volume information of the other ventilation fans received bythe information receiving portion with a total ventilation air volumeinformation in the building set in advance to determine the air volumeof its own fan so as to maintain the total ventilation air volume. Bythis configuration, a ventilation system having a plurality ofventilation fans installed in the same building can optimally maintain aventilation air volume required for the whole building and reduce anenergy loss caused by an excess of ventilation air volume.

In the ventilation system according to the seventh invention, the eighthinvention is characterized in that each ventilation fan comprises acommunication module having the information transmitting portion and theinformation receiving portion and is mounted on the module mount. Thisconfiguration allows a combination of a sensor module and thecommunication module to be mounted on the body unit, thereby making itpossible to provide a ventilation fan of a specification correspondingto an indoor environment while enabling communications with otherventilation fans.

Embodiments of the present invention are described hereinafter withreference to the drawings, but the present invention is not limited bythe embodiments.

Embodiment 1

FIG. 1 is a partially cutaway perspective view of a ventilation fanaccording to a first embodiment of the present invention, showing anexample of installation thereof, and FIG. 2 is an exploded perspectiveview of the ventilation fan.

As shown in FIG. 1 and FIG. 2, the ventilation fan 50 includes a bodyunit 51 having a box-shaped body case 1, and a fan 1 a mounted in thebody case 1. The body unit 51 is mounted on an upper surface of aceiling board 4. The body case 1 has an indoor air suction opening 2defined in a lower surface thereof and an indoor air discharge opening 3defined in a side surface thereof (this opening may be formed in anupper surface).

As shown in FIG. 1, the body case 1 is mounted on the upper surface ofthe ceiling board 4, which has an opening (not shown) of a size nearlyequal to that of the indoor air suction opening 2. The indoor airdischarge opening 3 in the body case 1 is connected to one end of a duct5, the other end of which is extended to outdoors.

A decorative board 6 is removably mounted so as to cover the indoor airsuction opening 2 from a lower surface of the ceiling board 4. Inmounting the decorative board 6 on the body case 1, a well-knownstructure is employed. By way of example, the decorative board 6 ismounted on the body case 1 by mounting attachment springs 7 to thedecorative board 6 and subsequently engaging the attachment springs 7with respective mounting portions 8 of the body case 1.

The decorative board 6 is formed so as to be greater than the indoor airsuction opening 2 in the body case 1 to cover the opening (not shown) inthe ceiling board 4 and the indoor air suction opening 2 from the lowersurface side of the ceiling board 4, thereby enhancing an aestheticaspect.

Also, the decorative board 6 has ventilation holes 9 and a modulemounting hole 10 all defined therein. The ventilation holes 9 are holesfor communicating the indoor air suction opening 2 in the body case 1with an indoor space to allow indoor air to pass therethrough. Asdescribed later, the module mounting hole 10 is a hole in which a sensormodule having an indoor environment detecting sensor installed thereinis mounted. In the ventilation fan 50 according to the first embodiment,selected from among a human body detecting sensor module 36 a having ahuman body detecting sensor installed therein, an illumination sensormodule 36 b having an illumination (illuminance) sensor installedtherein, and a humidity sensor module 36 c having a humidity sensorinstalled therein as the indoor environment detecting sensor, the humanbody detecting sensor module 36 a and the illumination sensor module 36b are mounted in the module mounting hole 10.

The body unit 51 is provided with a module mount 37 for mounting thereonthe two sensor modules 36 a, 36 b connected together via connectors. Themodule mount 37 is electrically connected to a fan controller providedin the body unit 51 to control the operation of the fan 1 a. The sensormodules 36 a, 36 b are mounted in the module mounting hole 10 in thedecorative board 6 by mounting the sensor modules 36 a, 36 b on themodule mount 37.

A control structure of the ventilation fan 50 is explained withreference to FIG. 3 depicting a control block diagram of the ventilationfan 50.

As shown in FIG. 3, the body unit 51 is provided with a fan controllerfor controlling the operation of the fan 1 a and a power unit 15 towhich the fan controller 14 and the fan 1 a are connected. The fancontroller 14 and the power unit 15 are mounted in, for example, thebody case 1.

The module mount 37 is provided with two connectors 16 a, 16 b toconnect the sensor modules 36 (36 a, 36 b). These connectors 16 a, 16 bare connected to the power unit 15 and the fan controller 14 to supplyelectric power from the power unit 15 to the sensor modules 36 and inputinformation from the sensor modules 36 to the fan controller 14 via theconnectors 16 a, 16 b.

The fan controller 14 is provided with a comparative arithmetic section35 (arithmetic section) for calculating and determining the air volumeof the fan 1 a with the use of an algorism (control logic) set inadvance based on the information (detected information) inputted fromthe sensor modules 36. The algorism used by the comparative arithmeticsection 35 is described later.

The human body detecting sensor module 36 a is provided with a humanbody detecting sensor 11 a, a module controller 12 a for controlling adetecting operation of the human body detecting sensor 11 a, asensitivity setting portion 32 a for setting the sensitivity of thehuman body detecting sensor 11 a, and a connector 38 a connected to themodule controller 12 a.

The human body detecting sensor 11 a has a function of detecting thepresence or absence of a person in a room and detects, for example,infrared rays emitted from the person to convert them into a voltage,and detects the presence or absence of the person based on a voltagechange. Such a human body detecting sensor 11 a is generally referred toas a pyroelectric sensor. It is sufficient if the human body detectingsensor 11 a has the function of detecting the presence or absence of aperson in a room, and any other form of sensor may be used.

The sensitivity setting portion 32 a is intended to set the sensitivitylevel of the human body detecting sensor 11 a and may include, forexample, a slide switch, a variable resistor or the like.

The module controller 12 a determines the air volume to be conveyed bythe fan 1 a, based on a detection signal from the human body detectingsensor 11 a and a sensitivity level set by the sensitivity settingportion 32 a, to output air volume information so determined as thedetected information to the fan controller 14. Also, the modulecontroller 12 a has a function of outputting identification informationof the indoor environment detecting sensor, i.e., identificationinformation of being a human body detecting sensor to the fan controller14.

The illumination sensor module 36 b is provided with an illuminationsensor 11 b, a module controller 12 b for controlling a detectingoperation of the illumination sensor 11 b, a sensitivity setting portion32 b for setting the sensitivity of the illumination sensor 11 b, and aconnector 38 b connected to the module controller 12 b. The illuminationsensor module 36 b is further provided with a night light 33 and anillumination driver 34 for activating the night light 33.

The illumination sensor 11 b has a function of detecting the indoorbrightness (illuminance) and, for example, a converter for convertingthe amount of light into a voltage is used. The sensitivity settingportion 32 b is intended to set the sensitivity level of theillumination sensor 11 b.

The module controller 12 b controls the lighting-up of the night light33 via the illumination driver 34 based on a detection signal from theillumination sensor 11 b and a sensitivity level set by the sensitivitysetting portion 32 b. Also, the module controller 12 b outputs to thefan controller 14 detected information including a detection result ofthe illumination sensor 11 b and the air volume to be conveyed by thefan 1 a. Further, the module controller 12 b has a function ofoutputting to the fan controller 14 identification information of theindoor environment detecting sensor, i.e., identification information ofbeing an illumination sensor.

The humidity sensor module 36 c is provided with a humidity sensor 11 c,a module controller 12 c for controlling a detecting operation of thehumidity sensor 11 c, a sensitivity setting portion 32 c for setting thesensitivity of the humidity sensor 11 c, and a connector 38 c connectedto the module controller 12 c.

The humidity sensor 11 c has a function of detecting the indoor humidityand, for example, a sensor of a resistance change type, a capacitancechange type or the like for converting a humidity change into a voltageis used. The sensitivity setting portion 32 c is intended to set thesensitivity level of the humidity sensor 11 c.

The module controller 12 c determines the air volume to be conveyed bythe fan 1 a, based on a detection signal from the humidity sensor 11 cand a sensitivity level set by the sensitivity setting portion 32 c, tooutput air volume information so determined as the detected informationto the fan controller 14. Also, the module controller 12 c has afunction of outputting to the fan controller 14 identificationinformation of the indoor environment detecting sensor, i.e.,identification information of being a humidity sensor.

The connectors 38 a-38 c of the sensor modules 36 a-36 c have a commonshape capable of being connected to the connectors 16 a, 16 b of themodule mount 37. For this reason, arbitrary sensor modules selected fromamong the plurality of indoor environment detecting sensor modules canbe connected to the connectors 16 a, 16 b of the module mount 37. Also,by disconnecting any one of the sensor modules connected once, anothersensor module can be connected.

In this first embodiment, the case where the human body detecting sensormodule 36 a and the illumination sensor module 36 b selected from amongthe plurality of indoor environment detecting sensor modules are mountedon the module mount 37 has been taken as an example, but any othersensor modules may be mounted.

The operation of the ventilation fan 50 is explained hereinafter withreference to an operation flowchart shown in FIG. 4.

As shown in FIG. 4, the power unit 15 of the ventilation fan 50 ispowered on under a condition where the human body detecting sensormodule 36 a and the illumination sensor module 36 b are connected to thebody unit 51 of the ventilation fan 50 via the connectors (S1).

In the human body detecting sensor module 36 a, the module controller 12a recognizes the sensitivity setting value of the sensitivity settingportion 32 a (S11) to initiate a detecting operation of the human bodydetecting sensor 11 a (S12). If the module controller 12 a determinesthat a person is present in a room based on the sensitivity settingvalue and a detection signal from the human body detecting sensor 11 a,a determination is made that the air volume to be conveyed by the fan 1a is to be set to a hi-air volume (strong wind) (S14). On the otherhand, if the module controller 12 a determines that no person is presentin the room, a determination is made that the air volume to be conveyedby the fan 1 a is to be set to a lo-air volume (weak wind) (S13). Themodule controller 12 a outputs (sends) the air volume information sodetermined to the fan controller 14 (S15) and, at the same time, outputs(sends) the identification information of the human body detectingsensor 11 a to the fan controller 14 (S16).

Also, in the illumination sensor module 36 b, the module controller 12 brecognizes the sensitivity setting value of the sensitivity settingportion 32 b (S21) to initiate a detecting operation of the illuminationsensor 11 b (S22). If the module controller 12 b determines that theindoor illuminance is low (dark) based on the sensitivity setting valueand a detection signal from the illumination sensor 11 b, theillumination driver 34 activates the night light 33 (S24). On the otherhand, if the module controller 12 b determines that the indoorilluminance is high (light), the illumination driver 34 deactivates thenight light 33 (S23). The module controller 12 b outputs (sends) alo-air volume (weak wind) as the air volume to be conveyed by the fan 1a together with such illuminance detection information to the fancontroller 14 (S25) and, at the same time, outputs (sends) theidentification information of the illumination sensor 11 b to the fancontroller 14 (S26).

Next, the comparative arithmetic section 35 of the fan controller 14executes processing of the information inputted from the sensor modules36 a, 36 b using an algorism set in advance. More specifically, adetermination is made as to whether or not the illumination sensormodule 36 b is connected based on the sensor identification informationinputted from the sensor modules (S31). As in this first embodiment, ifthe illumination sensor module 36 b is connected, a determination ismade as to whether the indoor illuminance is high or low (light or dark)with reference to the inputted illuminance information (detectioninformation) (S32). If information indicating that the indoorilluminance is low (dark) is inputted, a determination is made that theair volume to be conveyed by the fan 1 a is to be set to a lo-air volume(weak wind) (S35). On the other hand, if information indicating that theindoor illuminance is high (light) is inputted, the air volume of thefan 1 a is determined so as to prioritize large-air-volume information(S34) by comparing the air volume information inputted from the humanbody detecting sensor module 36 a with the air volume informationinputted from the illumination sensor module 36 b (S33). If adetermination is made that the illumination sensor module 36 b is notconnected (S31), upon comparison of the inputted air volume information(S33), the air volume of the fan 1 a is determined so as to prioritizethe large-air-volume information (S34).

The fan controller 14 gives an operation instruction (speed instruction)to the fan 1 a based on the air volume so determined (S41) to operatethe fan 1 a in the determined air volume (S42).

Also, even during the operation of the fan 1 a, the control operationsat these steps (S1-S42) are repeatedly conducted so that the fancontroller 14 can control the operation of the fan 1 a based on thedetection information of the sensor modules 36 a, 36 b.

The sensor module to be used as the indoor environment detecting sensorincludes a human body detecting sensor, a temperature sensor, a humiditysensor, an illumination sensor, a carbon monoxide sensor or a carbondioxide sensor. The operation flowchart of FIG. 4 takes the use of thehuman body detecting sensor module 36 a and the illumination sensormodule 36 b as an example, but any sensor module including a temperaturesensor, a humidity sensor, a carbon monoxide sensor or a carbon dioxidesensor is controlled at steps similar to those of the human bodydetecting sensor module 36 a. That is, in such a sensor module, the airvolume of the fan 1 a is determined to be set to either one of thehi-air volume and the lo-air volume based on the detection information.

Consideration is given to a case where a humidity sensor module and anillumination sensor module 36 b are mounted in the body unit 51, anillumination sensor 11 b detects that a room is dark, and a humiditysensor detects that the humidity is high. In this case, with an emphasison the detection information from the humidity sensor module rather thanthat from the illumination sensor module 36 b, the algorism in the fancontroller 14 may be weighted so as to set the air volume to a hi-airvolume. Upon input of the sensor identification information from therespective sensor modules to the fan controller 14, the fan controller14 identifies the kind of sensor modules mounted in the body unit 51 toperform a control based on an algorism appropriate for a combination ofthe sensors and the weighting. In this way, upon input of the sensoridentification information from the sensor modules mounted in the bodyunit 51 to fan controller 14, the control appropriate for the featuresand the combination of the respective sensors can be performed.

In the above discussion, an explanation has been made about a case wheretwo sensor modules 36 are selectively mounted on the sensor mount 37,but only one sensor module or more than three sensor modules may bemounted.

Also, the air volume of the fan 1 a has been described as being set toeither one of the hi-air volume and the lo-air volume, the former may beset to any one of a plurality of air volumes or may be set in anon-stepwise manner.

In the ventilation fan 50 according to the first embodiment referred toabove, various sensor modules 36 can be mounted in the body unit 51 in areplaceable manner. In particular, each sensor module 36 is providedwith a module controller 12 that controls the detecting operation of theindoor environment detecting sensor, determines the air volume to beconveyed by the fan 1 a, and outputs the air volume information to thefan controller 14 of the body unit 51. Because of this, the sensormodules 36 can control a detecting operation appropriate for therespective sensors, and a control specification of the fan controller 14can be made common with respect to various kinds of sensors, thus makingit possible to selectively mount the sensor modules 36 in the body unit51 depending on the functions required for an installation environmentusing the same body unit 51. Accordingly, the production or managementcost of the ventilation fan can be reduced.

Embodiment 2

A ventilation fan according to a second embodiment of the presentinvention is explained hereinafter with reference to the drawings.

In FIG. 5 to FIG. 7, a box-shaped body case 61 of the ventilation fanaccording to the second embodiment has an indoor air suction opening 62defined in a lower surface thereof and an indoor air discharge opening63 defined in a side surface (or an upper surface) thereof. A fan 61 ais accommodated within the body case 61.

As shown in FIG. 5, the body case 61 is mounted on an upper surface of aceiling board 64, which has an opening (not shown) of a size nearlyequal to that of the indoor air suction opening 62.

The indoor air discharge opening 63 in the body case 61 is connected toone end of a duct 65, the other end of which is extended to outdoors.

As shown in FIG. 5, the body case 61 is mounted on the upper surface ofthe ceiling board 64 and, in such a state, a decorative board 66 isremovably mounted so as to cover the indoor air suction opening 62 froma lower surface of the ceiling board 64.

In mounting the decorative board 66 on the body case 61, a well-knownstructure is employed. Specifically, this work can be easily done byengaging attachment springs 67 of the decorative board 66 withrespective mounting portions 68 of the body case 61.

The decorative board 66 has a shape greater than that of the indoor airsuction opening 62 in the body case 61. Accordingly, the decorativeboard 66 can cover an opening (not shown) in the ceiling board 64 andthe indoor air suction opening 62 from the lower surface side of theceiling board 64, thereby enhancing an aesthetic aspect.

Also, the decorative board 66 has ventilation holes 69 and a sensormounting hole 70 all defined therein. A human body detecting sensor (anexample of the indoor environment detecting sensor) 71 is mounted in thesensor mounting hole 70.

As shown in FIG. 8, the human body detecting sensor 71 is connected to acontroller 72, to which a wireless remote controller receiver 73 and afan controller 74 for controlling the fan 61 a within the body case 61are also connected.

The fan controller 74 is connected to the fan 61 a and a power unit 75.

The power unit 75 is also connected to the controller 72 mounted on thedecorative board 66 via a connector 76.

Further, the body case 61 is provided with a plurality of connectors 77(only one connector 77 is shown to avoid complexity of the drawing) inaddition to the connector 76.

That is, in the example shown in FIG. 5 to FIG. 7, the decorative board66 having the human body detecting sensor 71 mounted thereon is mountedin the indoor air suction opening 62 in the body case 61. In place ofthe decorative board 66, a decorative board 78 shown in FIG. 9 or adecorative board 79 shown in FIG. 10 may be mounted in the indoor airsuction opening 62 in the body case 61 depending on a difference inindoor environment.

By way of example, the decorative board 78 shown in FIG. 9 hasventilation holes 80 and a mounting hole 81 all defined therein. A humanbody detecting sensor (an example of the indoor environment detectingsensor) 71 and an illumination unit 82 are mounted in the mounting hole81.

In this case, as shown in FIG. 9, the illumination unit 82 is suppliedwith electric power via the connector 77 and controlled by thecontroller 72 connected to the illumination unit 82.

Further, in the decorative board 79 shown in FIG. 10, the mounting hole81 is used to mount the illumination unit 82 therein and anothermounting hole 84 is additionally provided to mount a separate indoorenvironment detecting sensor 83 therein.

The separate indoor environment detecting sensor 83 is at least one of,for example, a temperature sensor, a humidity sensor, a carbon monoxidesensor and a carbon dioxide sensor. As with the human body detectingsensor 71 of FIG. 8, this sensor is also connected to the controller 72.

This embodiment is characterized in that the operation of the decorativeboard 66, the decorative board 78 or the decorative board 79 can beperformed by the wireless remote controller 85 shown in FIG. 11 or FIG.12 with the decorative board mounted in the indoor air suction opening62 in the body case 61.

That is, in this embodiment, the decorative board 66, the decorativeboard 78 or the decorative board 79 is mounted in the indoor air suctionopening 62 in the body case 61 depending on an environment of a room inwhich the ventilation fan is installed, thereby making it possible toachieve a ventilation fan function depending on each environment.

Accordingly, the body case 61 can have a common specification and anyone of a plurality of decorative boards can be selectively mounteddepending on the environment, thus resulting in a reduction in variouscosts.

In order to realize the configuration of this embodiment, the fancontroller 74 is connected to the fan 61 a in the body case 61 and thewireless remote controller receiver 73 is connected to the controller 72of the decorative board 66, 78, 79.

Further, the controller 72 is connected to the fan controller 74 andconfigured such that a control operation can be changed by a signalreceived from the remote controller receiver 73.

By way of example, the air volume of the fan 61 a or the controloperation to be performed based on the human body detecting sensor (anexample of the indoor environment detecting sensor) 71 or any otherindoor environment detecting sensor 83 can be easily changed by acommand from the remote controller 85.

For this reason, it is not necessary to prepare a plenty of models torespond to various environments, thus resulting in a reduction invarious costs.

As with a known structure of a remote controller of, for example, an airconditioner, a basic structure of the remote controller 85 is created soas to emit infrared signals (an example of wireless type) and, hence,the following explanation is simplified to avoid complexity of theexplanation.

As shown in FIG. 11, a liquid crystal display 86 is provided on asurface of the remote controller 85. Also, an operating portion 87 forturning a ventilating function on and off, an operating portion 88 forturning the illumination unit 82 on and off, and an operating portion 89for turning a night illumination function on and off are provided belowthe display 86 on the surface.

Also, as shown in FIG. 12, an operating portion 91 for setting the airvolume of the fan 61 a is exposed by opening a lid 90 mounted on thesurface.

Infrared signals are emitted by operating the operating portions 87, 88,89 and received by the remote controller receiver 73 of FIG. 8 forsubsequent various settings.

Specifically, as shown in FIG. 5 to FIG. 7, when the decorative board 66has been mounted in the indoor air suction opening 62 in the body case61, the ventilating function is turned on by the operating portion 87 ofthe remote controller 85 and the air volume of the fan 61 a is set bythe operating portion 91.

That is, because the decorative board 66 is not provided with theillumination unit 82, the operating portions 88, 89 associated withillumination are not operated.

On the other hand, when the decorative board 78 of FIG. 9 or thedecorative board 79 of FIG. 10 has been mounted in the indoor airsuction opening 62 in the body case 61, the ventilating function isturned on by the operating portion 87 of the remote controller 85, theillumination unit 82 is turned on and off by the operating portion 88,the night illumination function is turned on and off by the operatingportion 89, and the air volume of the fan 61 a is subsequently set bythe operating portion 91.

That is, upon receipt of various setting instructions from the remotecontroller receiver 73 (S101 in FIG. 13), the controller 72 of FIG. 8makes operation settings based on the human body detecting sensor (anexample of the indoor environment detecting sensor) 71 (S102 in FIG.13), subsequently makes settings for the speed-dependent air volume(S202 in FIG. 14), an on-off operation of the illumination unit 82, anon-off operation of the night illumination function and the like (S103in FIG. 13), and then transmits fan control settings to the fancontroller 74 in the body case 61 (S104 in FIG. 13).

Upon receipt of an air volume instruction from the controller 72 (S201in FIG. 14), the fan controller 74 sets, for example, the fan speed atthe time of the lo-air volume (weak wind) (S202 in FIG. 14) and the fanspeed at the time of the hi-air volume (strong wind) (S203 in FIG. 14).Then, the fan controller 74 supplies the fan 61 a, in which adirect-current motor is used, with a direct-current voltage tailored tothe setting conditions (S204 in FIG. 14) to thereby drive the fan 61 a(S205 in FIG. 14).

When the fan 61 a is driven, indoor air is taken into the body case 61through the decorative board 66, the decorative board 78 or thedecorative board 79 and then discharged outdoors from the indoor airdischarge opening 63 through the duct 65, thereby providing ventilation.

As just described, in the second embodiment, any one of the decorativeboard 66, the decorative board 78 and the decorative board 79 is mountedin the indoor air suction opening 62 in the body case 61 depending on anenvironment of a room in which the ventilation fan is installed, therebymaking it possible to achieve a ventilation fan function depending oneach environment.

Accordingly, the body case 61 can be commonly used, thus resulting in areduction in various costs.

Although in the second embodiment referred to above the wireless remotecontroller receiver 73 has been described as being mounted on thedecorative board 78, the remote controller receiver 73 may be mounted onthe body case 61 side.

Also, although in the second embodiment the remote controller receiver73 has been described as being of a wireless type, it may be of a wiredtype. That is, in this case, the remote controller 85 referred to aboveis also of a wired type, and this wired type remote controller 85 andthe wired type remote controller receiver 73 are connected to each othervia lead wires.

Naturally, such a wired type remote controller receiver 73 may bemounted on the decorative board 78 or the body case 61.

As in the ventilation fan according to the second embodiment, the ideaof realizing a ventilation fan function tailored to each environment byselectively mounting the decorative board 6, 18, 19, on which the indoorenvironment detecting sensor 83 is mounted, in the indoor air suctionopening 62 in the body case 61 depending on an environment of a room inwhich a ventilation fan is installed is applicable to the ventilationfan according to the first embodiment referred to above. By way ofexample, ventilation fan functions can be realized depending on variousenvironments by replacing a decorative board having a sensor modulemounted thereon with another decorative board having a different sensormodule mounted thereon.

Also, the operations with the use of the remote controller 25 of theventilation fan according to the second embodiment are applicable to theventilation fan according to the first embodiment referred to above. Byway of example, if the remote controller receiver 73 is provided in themodule controller of the sensor module, communications can be performedbetween the remote controller and the module controller.

Embodiment 3

A ventilation fan according to a third embodiment of the presentinvention is explained hereinafter with reference to the drawings.

In FIG. 15 and FIG. 16, a box-shaped body case 101 of the ventilationfan according to the third embodiment has an indoor air suction opening102 defined in a lower surface thereof and an indoor air dischargeopening 103 defined in a side surface (or an upper surface) thereof. Afan 104 is accommodated within the body case 101.

As shown in FIG. 15, the body case 101 of the ventilation fan is mountedon an upper surface of a ceiling board 105, which has an opening (notshown) of a size nearly equal to that of the indoor air suction opening102. The indoor air discharge opening 103 in the body case 101 of theventilation fan is connected to one end of a duct 106, the other end ofwhich is extended outdoors.

Also, as shown in FIG. 15, the body case 101 is mounted on the uppersurface of the ceiling board 105. In such a state, a decorative board107 is removably mounted so as to cover the indoor air suction opening102 from a lower surface of the ceiling board 105.

In mounting the decorative board 107 on the body case 101, a well-knownstructure is employed. Briefly explaining, this work can be easily doneby engaging attachment springs 108 of the decorative board 107 withrespective mounting portions 109 of the body case 101.

Because the decorative board 107 is greater than the indoor air suctionopening 102 in the body case 101, the decorative board 107 can cover anopening (not shown) in the ceiling board 105 and the indoor air suctionopening 102 from the lower surface side of the ceiling board 105,thereby enhancing an aesthetic aspect while ensuring air permeability.

As shown in FIG. 16, the decorative board 107 has ventilation holes 110and an indoor environment detecting unit-mounting hole 111 all definedtherein. An indoor environment detecting unit 112 (for example, a humanbody detecting sensor) having at least one sensor is mounted in theindoor environment detecting unit-mounting hole 111.

Also, as shown in FIG. 16, the body case 101 accommodates a contactlesspower transmitting unit 113 therein, which supplies the decorative board107 side with electric power in a contactless manner and receives acontrol operation signal of the fan 104 from the decorative board 107side.

The decorative board 107 is provided with a decorative board-contactlesspower transmitting unit 114 disposed at a location confronting thecontactless power transmitting unit 113 so as to receive electric powerfrom the contactless power transmitting unit 113 and to send the controloperation signal of the fan 104 to the contactless power transmittingunit 113.

The decorative board 107 is also provided with a controller 115connected to the decorative board-contactless power supply unit 114 soas to work upon receipt of power supply.

As shown in FIG. 17, the contactless power transmitting unit 113includes a power transmitting means 117 for receiving power supply froma power unit 116, which rectifies and smooths a commercially availablepower source provided in the body case 101 to generate a desiredvoltage, to supply the decorative board 107 side with electric power.The contactless power transmitting unit 113 also includes a receivingmeans 118 for receiving a control operation signal of the fan 104 fromthe decorative board 107 side.

The receiving means 118 is connected to a fan controller 119 thatcontrols the fan 104 based on the control operation signal of the fan104 received from the decorative board 107 side.

The power transmitting means 117 includes, for example, anelectromagnetic induction coil for transmitting electric power using aninductive current produced by a magnetic field between opposed coils.The receiving means 118 includes, for example, an electromagneticinduction coil for transmitting a communication signal using aninductive current produced by a magnetic field between opposed coils.

Also, as shown in FIG. 17, the decorative board-contactless powertransmitting unit 114 confronting the contactless power transmittingunit 113 includes a power receiving means 120 for receiving electricpower from the power transmitting means 117 of the contactless powertransmitting unit 113 and a transmitting means 121 for transmitting acontrol operation signal to the receiving means 118.

The power receiving means 120 includes, for example, an electromagneticinduction coil for transmitting electric power using an inductivecurrent produced by a magnetic field between opposed coils. Thetransmitting means 121 includes, for example, an electromagneticinduction coil for transmitting a communication signal using aninductive current produced by a magnetic field between opposed coils.

As shown in FIG. 17, the controller 115 is provided with an indoorenvironment detecting unit 112, an operation decision portion 122 fordetermining the operation of the fan 104 based on an environmentdetected by the indoor environment detecting unit 112, and a controloperation signal-generating portion 123 for outputting a controloperation signal to the transmitting means 121 based on the operationdetermined by the operation decision portion 122.

In the above-described configuration, because the indoor environmentdetecting unit 112 is comprised of a human body detecting sensor, if aperson in a room is not detected, the operation decision portion 122determines, upon receipt of a detection signal from the indoorenvironment detecting unit 112, a lo-air volume (for example, 50 m³/h)as a minimum air volume required for ventilation of indoor air with theuse of the air volume of the fan 104.

Next, if a person in a room is detected, the detection signal from theindoor environment detecting unit 112 is transmitted to the operationdecision portion 122 of the controller 115, which in turn compares thedetection signal with an arbitrary threshold value to determine a changefrom the previously-determined lo-air volume (for example, 50 m³/h) ofthe fan 104 to a hi-air volume (for example, 100 m³/h) as a given airvolume of the fan 104 at a time when the person is detected in the room.

The control operation signal-generating portion 123 outputs thegenerated control operation signal based on the determined air volume tothe transmitting means 121 of the decorative board-contactless powertransmitting unit 114. The control operation signal transmitted to thetransmitting means 121 is then transmitted to the fan controller 119through the receiving means 118 of the contactless power transmittingunit 113 so that the fan controller 119 may change the air volume of thefan 104 from the lo-air volume to the hi-air volume.

Also, when no person is detected, after a lapse of a predeterminedperiod of time (for example, ten minutes), the operation decisionportion 122 determines the air volume to be conveyed by the fan 104 (forexample, the previously-set air volume (lo-air volume)), and the airvolume so determined is transmitted as the control operation signal fromthe decorative board-contactless power transmitting unit 114 to the fancontroller 119 through the contactless power transmitting unit 113. Bydoing so, the fan controller 119 changes the air volume of the fan 104from the hi-air volume to the lo-air volume.

As just described, in the third embodiment, the contactless powertransmitting unit 113 supplies the decorative board-contactless powertransmitting unit 114 with electric power to operate the controller 115.

Also, in the controller 115, the operation decision portion 122determines the operation of the fan 104 based on the detection signaldetected by the indoor environment detecting unit 112, and the controloperation signal-generating portion 123 generates a control operationsignal corresponding to the operation determined by the operationdecision portion 122.

The control operation signal so generated is transmitted to thecontactless power transmitting unit 114 through the decorativeboard-contactless power transmitting unit 114 and then to the fancontroller 119.

The fan controller 119 changes the control operation of the fan 104based on the control operation signal referred to above, thus making itpossible to easily realize the control operation based on the indoorenvironment detecting unit 112.

That is, the operation of the fan 104 can be determined and changed bythe operation decision portion 122 based on the indoor environmentdetected by the indoor environment detecting unit 112.

In summary, the controller 115 of the decorative board 107 is suppliedwith electric power that has been received by the power receiving means120 from the contactless power transmitting unit 113 on the body case101 side. Then, the operation decision portion 122 determines theoperation of the fan 104 based on the indoor environment detected by theindoor environment detecting unit 112, and the control operationsignal-generating portion 123 outputs the control operation signal tothe transmitting means 121 based on the determined operation of the fan104. The control operation signal is subsequently received by thereceiving means 118 of the body case 101 to allow the fan controller 119to control the fan 104, thus making it possible to perform transmissionand reception of the electric power and the signals in a contactlessmanner.

That is, without the need of a wired connection, various problems causedby the wired connection, i.e., a loss in air volume and wind noisescaused by an airflow disturbance of the fan 104 can be reduced. Inaddition to this, wires connected to the sensor of the decorative board107 for power supply and communication signals are not required, thusenhancing convenience during cleaning or maintenance.

As in the ventilation fan according to the third embodiment, the idea ofperforming power supply and transmission of the control operation signalin a contactless manner between the contactless power transmitting unit113 mounted in the body case 101 and the decorative board-contactlesspower transmitting unit 114 mounted on the decorative board 107 isapplicable to the ventilation fan according to the first embodimentreferred to above. By way of example, the sensor module and the bodyunit may be provided with respective contactless power transmittingunits so that power supply and transmission of the control operationsignal may be performed in a way that the sensor module is notwire-connected to the fan controller of the body unit. In thisconfiguration, wires for power supply to the sensor module and forcommunication signals are not required, thus enhancing convenienceduring cleaning or maintenance and facilitating replacement of thesensor module.

Embodiment 4

A ventilation fan according to a fourth embodiment of the presentinvention is explained hereinafter with reference to the drawings.

In FIG. 18 and FIG. 19, a box-shaped body case 201 of the ventilationfan according to the fourth embodiment has a square indoor air suctionopening 202 defined in a lower surface thereof and an indoor airdischarge opening 203 defined in a side surface (or an upper surface)thereof. A fan 204 is accommodated within the body case 201.

As shown in FIG. 18, the body case 201 of the ventilation fan is mountedon an upper surface of a ceiling board 205, which has an opening (notshown) of a size equal to that of the indoor air suction opening 202.The indoor air discharge opening 203 in the body case 201 of theventilation fan is connected to one end of a duct 206, the other end ofwhich is extended to outdoors.

Also, as shown in FIG. 18, the body case 201 is mounted on the uppersurface of the ceiling board 205. In such a state, a decorative board207 is mounted so as to cover the indoor air suction opening 202 from alower surface of the ceiling board 205.

In consideration of the ease of forming the opening in the ceilingboard, the indoor air suction opening 202 is in the form of a square.

Because the decorative board 207 is greater than the indoor air suctionopening 202 in the body case 201, the decorative board 207 can cover anopening (not shown) in the ceiling board 205 and the indoor air suctionopening 202 from the lower surface side of the ceiling board 205,thereby enhancing an aesthetic aspect while ensuring air permeability.

The decorative board 207 is formed into a square in conformity with theshape of the indoor air suction opening 202 and can be accordinglyremovably mounted in any one of a plurality of directions with a centerthereof positioned on a center of the body case.

In mounting the decorative board 207 on the body case 201, a well-knownstructure is employed. Specifically, as shown in FIG. 19, this work canbe easily done by engaging two attachment springs 208, which are mountedto the decorative board 207 at opposed two sides, with respectivemounting portions 209 of the body case 201.

As shown in FIG. 19, the decorative board 207 has ventilation holes 210and an indoor environment detecting unit-mounting hole 211 all definedtherein.

The ventilation holes 210 are positioned at a central portion of thedecorative board 207 and the indoor environment detecting unit-mountinghole 211 is positioned at a corner portion of the decorative board 207.

An indoor environment detecting unit 212 (for example, a human bodydetecting sensor) having at least one sensor is mounted in the indoorenvironment detecting unit-mounting hole 211.

As shown in FIG. 19, the mounting portions 209 are positioned at fourlocations along respective sides of the indoor air suction opening 202and, hence, the decorative board 208 can be mounted on the body case 201in any one of a plurality of directions by rotating the attachmentsprings 208 with respect to the mounting portions 209 at angularintervals of 90 degrees.

As shown in FIG. 21, the attachment springs 208 are positioned adistance Y away from the center of the decorative board 207.

Also, the configuration of the attachment springs 208 and the mountingportions 209 can be realized, for example, in such a way that clawsformed on or with the decorative board 207 are engaged with those formedon or with the body case 201.

Also, the number of orientations of the decorative board 207 can beincreased by forming the indoor air suction opening 202 and thedecorative board 207 into a point-symmetric shape (for example, acircle, a regular polygon or the like).

As shown in FIG. 19, the body case 201 accommodates therein a powersupply unit 213 for generating a desired voltage by rectifying andsmoothing a commercially available power source and a body sidecontactless power transmitting and receiving unit 215 positioned apredetermined distance X away from the center of the body case 201 in alateral direction.

The body side contactless power transmitting and receiving unit 215includes a body side coil unit 214 for receiving power supply from thepower supply unit 213 to supply the decorative board 207 side withelectric power in a contactless manner and for receiving a controloperation signal of the fan 204 from the decorative board 207 side.

As shown in FIG. 21, it is particularly preferred that the body sidecoil unit 214 of the body side contactless power transmitting andreceiving unit 215 be positioned at a location laterally a predetermineddistance X away from the center of the body case 201.

Also, as shown in FIG. 20, the body side contactless power transmittingand receiving unit 215 is connected to a fan controller 219 thatcontrols the fan 204 based on the control operation signal of the fan204 received from a decorative board side contactless power transmittingand receiving unit 217.

The decorative board 207 is provided with the decorative board sidecontactless power transmitting and receiving unit 217 and a controller218 connected to the decorative board side contactless powertransmitting and receiving unit 217 to work upon receipt of powersupply.

The decorative board side contactless power transmitting and receivingunit 217 includes a decorative board side coil unit 216 for receivingpower supply from the body side contactless power transmitting andreceiving unit 215 and for transmitting the control operation signal ofthe fan 204 to the body side contactless power transmitting andreceiving unit 215.

As shown in FIG. 21, the decorative board side coil unit 216 isannularly disposed along and in parallel to respective sides of thedecorative board 207 so as to pass through locations a predetermineddistance X away from the center of the decorative board 207.

That is, the decorative board side coil unit 216 is in the form of asquare analogous to the shape of the decorative board 207 so as to beformed along the periphery thereof. By this configuration, as shown inFIG. 21, the body side contactless power transmitting and receiving unit215 or the body side coil unit 214 is positioned above the decorativeboard side coil unit 216.

Also, it is preferred that the predetermined distance X be smaller thana distance Y from the center of the decorative board 207, at which theattachment springs 208 are positioned.

That is, the body side coil unit 214 or the body side contactless powertransmitting and receiving unit 215 is positioned inwardly of theinstallation locations of the attachment springs 208. Because thedecorative board side coil unit 216 is provided with the body sidecontactless power transmitting and receiving unit 215, the former issimilarly positioned inwardly of the installation locations of theattachment springs 208.

As shown in FIG. 20, the controller 218 is provided with an indoorenvironment detecting unit 212, an operation decision portion 220 and acontrol operation signal-generating portion 221.

The operation decision portion 220 determines the operation of the fan204 based on an environment detected by the indoor environment detectingunit 212.

The control operation signal-generating portion 221 outputs a controloperation signal to the decorative board side contactless powertransmitting and receiving unit 217 based on the operation determined bythe operation decision portion 220.

The body side contactless power transmitting and receiving unit 215 hasa function of transmitting electric power, for example, by magneticallyresonating a resonator made up of a capacitor disposed in series withthe body side coil unit 214. Similarly, the decorative board sidecontactless power transmitting and receiving unit 217 has a function oftransmitting electric power, for example, by magnetically resonating aresonator made up of a capacitor disposed in series with the decorativeboard side coil unit 216.

As just described, because electric power is transmitted by magneticallyresonating the resonator, if a projection plane of the body sidecontactless power transmitting and receiving unit 215 or the body sidecoil unit 214 overlaps with the decorative board side coil unit 216,transmission of electric power and transmission and reception of signalsare possible.

In this fourth embodiment, the decorative board side coil unit 216 is inthe form of a square analogous to the shape of the decorative board 207so as to be formed along the periphery thereof and, accordingly, theformer is disposed over a much broader range than the body side coilunit 214.

In the above-described configuration, the body side contactless powertransmitting and receiving unit 215 supplies the decorative board sidecontactless power transmitting and receiving unit 217 with electricpower to operate the controller 218.

The operation decision portion 220 in the controller 218 has anarbitrary threshold value and compares a detection signal of the indoorenvironment detecting unit 212 with the arbitrary threshold value totransmit an operation signal corresponding to the predetermined airvolume of the fan 204. The operation signal is then sent to the controloperation signal-generating portion 221.

By way of example, if the detection signal of the indoor environmentdetecting unit 212 is less than the threshold value, an operation signalindicating a lo-air volume (for example, 30 m³/h) as the air volume ofthe fan 204 is transmitted, and if the detection signal of the indoorenvironment detecting unit 212 is greater than or equal to the thresholdvalue, an operation signal indicating a hi-air volume (for example, 50m³/h) is transmitted.

As described above, in the controller 218, the operation decisionportion 220 determines the operation of the fan 204 (air volume to beconveyed) based on the signal detected by the indoor environmentdetecting unit 212, and the control operation signal-generating portion221 generates a control operation signal corresponding to the operationdetermined by the operation decision portion 220.

The control operation signal generated in this way is sent to the bodyside contactless power transmitting and receiving unit 215 via thedecorative board side contactless power transmitting and receiving unit217 and then to the fan controller 219.

Because the fan controller 219 changes the control operation of the fan204 based on the above-described control operation signal, the operationcontrol of the fan 204 can be easily realized based on the indoorenvironment detecting unit 212.

In summary, the controller 218 of the decorative board 207 is suppliedwith electric power that has been received by the decorative board sidecontactless power transmitting and receiving unit 217 from the body sidecontactless power transmitting and receiving unit 215 for subsequentoperation of the operation decision portion 220.

The operation decision portion 220 determines the operation of the fan204 (air volume to be conveyed) based on the indoor environment detectedby the indoor environment detecting unit 212.

The control operation signal-generating portion 221 outputs the controloperation signal to the decorative board side contactless powertransmitting and receiving unit 217 based on the operation of the fan204 determined by the operation decision portion 220.

The above-described control operation signal is received by the bodyside contactless power transmitting and receiving unit 215 to allow thefan controller 219 to control the fan 204, thus making it possible totransmit and receive electric power and signals in a contactless mannerand to dispense with lead wires between the body case 201 and thedecorative board 207.

A positional relationship between the body side coil unit 214 and thedecorative board side coil unit 216, which characterizes the fourthembodiment, is explained hereinafter.

The configuration has been already explained, but as shown in FIG. 21,the body side coil unit 214 is positioned at a location laterally apredetermined distance X away from the center of the body case 201.Also, the decorative board side coil unit 216 is in the form of a squareanalogous to the shape of the decorative board 207 at a location thepredetermined distance X away from the center of the decorative board207 so as to be formed along the periphery thereof.

By this configuration, the body side coil unit 214 is positioned at alocation on one side of the decorative board side coil unit 216.Accordingly, even if the location of the decorative board side coil unit216 is changed by changing the mounting direction of the decorativeboard 207, the distance between the body side coil unit 214 and thedecorative board side coil unit 216 can be maintained constant. That is,the decorative board side contactless power transmitting and receivingunit 217 can transmit and receive electric power and signals to and fromthe body side contactless power transmitting and receiving unit 215irrespective of the mounting direction of the decorative board 207.

Also, the decorative board side coil unit 216 or the body sidecontactless power transmitting and receiving unit 215 is positionedinwardly of the installation locations of the attachment springs 208.

This configuration does not allow the body side coil unit 214 and thedecorative board side coil unit 216 to interfere with each other even byrotation of the decorative board 207, thus making it possible to changethe mounting direction by rotation of the decorative board 207.

Also, because the indoor environment detecting unit 212 is positioned ata corner portion of the decorative board 207, the attachment springs 208does not interfere with the mounting portions 209. Accordingly, thedetection area of the indoor environment detecting unit 212 can beadjusted merely by changing the mounting direction of the decorativeboard 207.

As described above, the mounting direction of the decorative board 207can be easily changed without the need of connecting the body case 201and the decorative board 207 with lead wires.

Also, the detection area of the indoor environment detecting unit 212can be adjusted merely by changing the mounting direction of thedecorative board 207. That is, the mounting direction of the decorativeboard 207 can be changed in accordance with the structure of a house inwhich the ventilation fan is installed, and the detection area of theindoor environment detecting unit 212 can be changed to an optimal one,thus making it possible to realize a highly convenient ventilation fan.

As in the ventilation fan according to the fourth embodiment, the ideaof devising the positional relationship and configurations of the bodyside coil unit 214 and the decorative side coil unit 216 to adjust thedetection area of the indoor environment detecting unit 212 mounted onthe decorative board 207 merely by changing the mounting direction ofthe decorative board 207 is applicable to the ventilation fan accordingto the first embodiment referred to above. By way of example, if asensor module is mounted on a decorative board so as to be connected tothe decorative board side coil unit, the detection area of a sensor ofthe sensor module can be adjusted by changing the mounting direction ofthe decorative board. Also, when the sensor module is replaced withanother sensor module, the detection area can be adjusted to suit for aspecification of a sensor mounted in the latter.

The ventilation fans according to the embodiments referred to above doaway with the need to prepare many kinds of ventilation fans to copewith various indoor environments, thus resulting in a reduction invarious costs. Accordingly, they are expected to be used as ventilationfans that can be mounted on a ceiling.

Embodiment 5

A ventilation system according to a fifth embodiment of the presentinvention is explained hereinafter. In the ventilation system accordingto this fifth embodiment, a plurality of ventilation fans are connectedto one another via a communication network so that a fan control of eachfan is performed with reference to fan control information of otherfans.

FIG. 22 and FIG. 23 depict a ventilation fan provided in the ventilationsystem according to this fifth embodiment. A body case 301 of theventilation fan is a box-shaped body case having an indoor air suctionopening 302 defined in a lower surface thereof and an indoor airdischarge opening 303 defined in a side surface (or an upper surface)thereof. A fan 304 is accommodated within the body case 301.

As shown in FIG. 22, the body case 301 of this ventilation fan ismounted on an upper surface of a ceiling board 305, which has an opening(not shown) of a size nearly equal to that of the indoor air suctionopening 302.

The indoor air discharge opening 303 in the body case 301 of theventilation fan is connected to one end of a duct 306, the other end ofwhich is extended to outdoors.

As shown in FIG. 22, the body case 301 is mounted on the upper surfaceof the ceiling board 305 and, in such a state, a decorative board 308having slit-like ventilation holes 307 defined therein is removablymounted so as to cover the indoor air suction opening 302 from a lowersurface of the ceiling board 305.

In mounting the decorative board 308 on the body case 301, a well-knownstructure is employed. Briefly explaining, as shown in FIG. 23, thiswork can be easily done by engaging attachment springs 309 of thedecorative board 308 with respective mounting portions 310 of the bodycase 301. The decorative board 308 is formed so as to be greater thanthe indoor air suction opening 302 in the body case 301. Because ofthis, the decorative board 308 can cover an opening (not shown) in theceiling board 305 and the indoor air suction opening 302 from the lowersurface side of the ceiling board 305, thereby enhancing an aestheticaspect.

Also, a floor area-setting portion 311 is mounted to the body case 301at a location where a user can easily confirm and operate the floorarea-setting portion 311, upon removal of the decorative board 308, toset a rough total floor area of a whole building (total floor area of aplurality of rooms), in which respective ventilation fans of theventilation system are mounted. As shown in FIG. 24(a), the floorarea-setting portion 311 is provided with a dial switch capable ofsetting a room layout (that is, the total floor area) of the building inany one of a plurality of ranges, but any other switch than the dialswitch may be used if it enables selective setting.

In the construction industry, it is common to determine the air volumethat should be secured depending on the floor area of a building. Forthis reason, as shown in FIG. 24(b), a total ventilation air volumerequired for the building is defined depending on the floor layout(total floor area).

A block diagram of a control circuit of the ventilation system isexplained hereinafter with reference to FIG. 25.

Each block of the control circuit of the ventilation system includes apower circuit 313 connected to a commercially available power source312, a fan 304 such as, for example, a DC motor having three-phase (U, Vand W phases) stator windings connected to output voltage terminals ofthe power circuit 313 via, for example, a drive IC 314 that is anaggregate of switching elements such as FETs, a controller 315 forexecuting various information processing to control the speed of the fan304, a floor area-setting portion 311 connected to the controller 315 toset floor area information of a building, an information transmittingportion 316 for transmitting information to other ventilation fans, andan information receiving portion 317 for receiving information from theother ventilation fans.

The controller 315 is driven with a DC5V or DC3V output voltage of thepower circuit 313 and includes a CPU (Central Processing Unit). Theoperation of the controller 315 explained later is conducted in the formof a program in which a counter, a RAM and a Rom cooperate with oneanother within the controller 15.

Also, the controller 315 transmits and receives air volume informationof the ventilation fan and floor area information of the building set bythe floor area-setting portion 311 to and from the other ventilationfans via the information transmitting portion 316 and the informationreceiving portion 317. Even if either one of a wired connection and awireless connection is employed for connection of the informationtransmitting portions 316 and the information receiving portions 317 ofthe respective ventilation fans, similar effects are promising.

Further, the controller 315 is provided with a total ventilation airvolume decision means 318 and a first air volume decision means 319.

The total ventilation air volume decision means 318 compares the floorarea information set by the floor area-setting portion 311 of a firstventilation fan 320 employed as one ventilation fan with the floor areainformation set by the floor area-setting portion 311 of a secondventilation fan 321 employed as another ventilation fan to recognizegreater floor area information as the total floor area of the buildingand to set air volume information corresponding to this total floor areastored in the CPU in advance to the required total ventilation airvolume.

The first air volume decision means 319 determines the air volume of theself based on the total ventilation air volume determined by the totalventilation air volume decision means 318 of the first ventilation fan320 and the information of the second ventilation fan 321 to adjust theair volume of the fan 304.

An air volume control operation of the ventilation fan in theventilation system of the above-described configuration is explainedwith reference to a flowchart shown in FIG. 26.

The flowchart shown in FIG. 26 includes a flow (step S301) of obtainingthe information set by the floor area-setting portion 311 of the firstventilation fan 320 and that of another fan, i.e., the secondventilation fan 321 installed in the same building, a flow (step S302)of indicating the total ventilation air volume decision means 318, and aflow (step S303) of indicating the first air volume decision means 319.

It is assumed here that the ventilation system includes two ventilationfans having the same specification including a maximum air capacity of150 [m²/h] and installed in a building having a total floor area greaterthan or equal to 751 m² and that the two ventilation fans are the firstventilation fan 320 and the second ventilation fan 321, respectively.This ventilation system is hereinafter explained in detail.

At step S301, when the first ventilation fan 320 and the secondventilation fan 321 are supplied with electric power, the floor areainformation set by the floor area-setting portions 311 of the twoventilation fans is recognized. By way of example, it is assumed thatthe setting value of the first ventilation fan 320 is S1=751 [m²] orgreater and the setting value of the second ventilation fan 321 isS2=451-600 [m²]. In this case, the first ventilation fan 320 transmitsthe information S1 to the second ventilation fan 321 and the secondventilation fan 321 transmits the information S2 to the firstventilation fan 320, thereby completing a two-way communication andmaking it possible to recognize each other's floor area information andthat two ventilation fans are connected to each other within the samebuilding.

At subsequent step S302, the operation of the total ventilation airvolume decision means 318 is explained. The total ventilation air volumedecision means 318 compares the information S1 and the information S2with each other and recognizes a greater value, i.e., the information ofS1=751 [m²] or greater here as the total floor area information of thebuilding. The controller 315 stores table data of FIG. 24(b) therein andconverts such information into a total ventilation air volume of Q=250[m³/h] required for the building corresponding to S1=751 [m²] or greaterto recognize the latter.

At subsequent step S303, the operation of the first air volume decisionmeans 319 is explained.

Because the maximum air capacity of the first ventilation fan 320 andthat of the second ventilation fan 321 are both 150 [m³/h], when the twoventilation fans are operated at the maximum capacity at the same time,the total ventilation air volume becomes equal to 150×2=300 [m³/h], thusresulting in an air volume excess state by 50 [m³/h] with respect to therequired total ventilation air volume of Q=250 [m³/h].

Accordingly, based on the information recognized at step S301 andindicating that the two ventilation fans are connected within the samebuilding and on the information recognized at step S302 and indicatingthat the total ventilation air volume required for the building is Q=250[m³/h], the air volume required for each ventilation fan is determinedas being Q1=Q/N=250/2=125 [m³/h].

A general practice is such that the indoor air discharge opening 303 inthe body case 301 of the ventilation fan is connected to one end of theduct 306, the other end of which is extended outdoors and, hence, thepressure loss increases or decreases and the initially determined airvolume cannot be secured in some circumstances.

There are not any problems if both the ventilation fans can show thecapacity of 125 [m³/h], for example, when the length of the duct 306 ofthe first ventilation fan 320 is nearly equal to that of the duct 306 ofthe second ventilation fan 321.

However, if the duct 306 of the second ventilation fan 321 is installed,for example, at a length over a designed allowable length, the secondventilation fan 321 can sometimes show only an air capacity of QN=110[m³/h].

In such a case, the air volume may be detected using a sensor (notshown) mounted in the duct 306 or based on information of an electriccurrent or speed of the fan 304.

The air volume of the first ventilation fan 320 is subsequently adjustedagain to an air volume of Q1′=250−110=140 [m³/h] so as to ensure thetotal ventilation air volume of Q=250 [m³/h] required for the building,thereby making it possible to determine the air volumes of both theventilation fans to hold the ventilation air volume of the buildingconstant.

Although the ventilation system according to this fifth embodiment hasbeen explained as having two ventilation fans, similar effects can beobtained even if the number of the ventilation fans increases.

As described above, in this fifth embodiment, all the ventilation fansof the ventilation system obtain mutual information so that theventilation fans may be operated by determining the ventilation airvolume of each ventilation fan based on the information obtained by thetotal ventilation air volume decision means 318 and the informationabout the air volumes and the number of the ventilation fans installedin the same building. By doing so, even in an environment where thetotal ventilation capacity of the respective ventilation fans isexcessive for the total ventilation air volume required for the wholebuilding, the ventilation fans can be controlled to reduce therespective air volumes without any subordinate-superior relationshipamong the ventilation fans, thereby making it possible to optimallymaintain the air volume required for the whole building.

Embodiment 6

A configuration of a ventilation system according to a sixth embodimentof the present invention is explained with reference to FIG. 27 to FIG.29.

The same component parts as those of the ventilation system according tothe fifth embodiment referred to above are designated by the same signsand explanation thereof is omitted.

As shown in FIG. 27, a decorative board 308 has ventilation holes 307and an environment detecting unit-mounting hole 322 all defined therein,and an environment detecting unit 323 is mounted in the environmentdetecting unit-mounting hole 322. The environment detecting unit 323(that is, an indoor environment detecting sensor) is made up of at leastone of a human body detecting sensor, a temperature sensor, a humiditysensor, a carbon monoxide sensor and a carbon dioxide sensor.

As shown in a block diagram of a control circuit of the ventilationsystem of FIG. 28, the environment detecting unit 323 is connected to acontroller 315, which recognizes changes of various sensor signals ofthe environment detecting unit 323.

The controller 315 includes a second air volume decision means 324provided therein in the form of a program to determine a new air volumethereof based on total air volume information determined by a totalventilation air volume decision means 318 and the information of thevarious environmental changes detected by the above-describedenvironment detecting unit 323 to thereby adjust the air volume of a fan304.

An example in which various sensors of the environment detecting unit323 include, for example, a human body detecting sensor 325 fordetecting the presence or absence of a human body is explainedhereinafter.

In this configuration, an air volume control operation of theventilation system according to the sixth embodiment is explained withreference to a flowchart shown in FIG. 29.

At step S304, the operation of the second air volume decision means 324is explained.

It is assumed that in an environment where a total ventilation airvolume of Q=250 [m³/h] is required for a building, the first ventilationfan 320 and the second ventilation fan 321 are being operated at an airvolume of Q1′=125 [m³/h] determined by the first air volume decisionmeans 319.

If the human body detecting sensor 325 in the environment detecting unit323 of the first ventilation fan 320 detects a human body, thecontroller 315 recognizes a detection signal.

In order to forcibly discharge dirty air outside, the controller 315controls the speed of the fan 304 to change the air volume to Q2=150[m³/h], i.e., a maximum air capacity of the first ventilation fan 320.Because the air volume of the second ventilation fan 321 is stillQ1′=125 [m³/h], the total ventilation air volume becomes equal to150+125=275 [m³/h], thus resulting in an air volume excess state by 25[m³/h] with respect to the total ventilation air volume of Q=250 [m³/h]required for the building.

Because of this, the first ventilation 320 transmits its own changed airvolume of Q2=150 [m³/h] to the second ventilation fan 321, which in turnconfirms the detection signal of the environment detecting unit 323. Ifthe detection signal indicates a non-detection state, the secondventilation fan 321 calculates its own air volume QN′ based on the newair volume Q2 of the first ventilation fan 320. Based on the totalventilation air volume of Q=250 [m³/h] required for the building, thepresent air volume of Q2=150 [m³/h] of the first ventilation fan 320,and information about the number N of ventilation fans connectedtogether in the building, the air volume QN′ is calculated as follows:

QN′=(Q−Q2)/(N−2)=(250−150)/(2−1)=100 [m³/h].

The second ventilation fan 321 changes its own air volume to QN′=100[m³/h] and transmits a change completion signal QN′ to the firstventilation fan 320. The first ventilation fan 320 confirms that a sumof the air volume information of QN′=100 [m³/h] transmitted from thesecond ventilation fan 321 and its own air volume of Q2=150 [m³/h] isequal to the total air volume of Q=250 [m³/h] required for the buildingand finally determines the air volume of the first ventilation fan 320as being Q2′=150 [m³/h]. If a person exits a room and the human bodydetecting sensor 325 detects no person, the program returns to stepS303, at which the respective ventilation fans are operated at an airvolume of Q1′=125 [m³/h].

If the human body detecting sensors 325 of both the first ventilationfan 320 and the second ventilation fan 321 detect a person, dirty air ineach space is forcibly discharged outside. For this reason, therespective ventilation fans are operated at Q2′=Q3=150 [m³/h] topreferentially ensure the required ventilation air volumes and,accordingly, a ventilation air volume excess state continues for a givenperiod of time, but when the human body detecting sensors 325 detect noperson and after dirty air has been discharged, the program returns tostep S303, at which the respective air volumes are changed to Q1′=125[m³/h], thus resulting in a state where the original total air volume ofQ=250 [m³/h] is maintained.

Although the ventilation system according to the sixth embodiment hasbeen described as having, for example, two ventilation fans, similareffects can be obtained even if the number of the ventilation fansincreases.

As described above, in the ventilation system according to the sixthembodiment, all the ventilation fans of the ventilation system obtainmutual information so that the ventilation fans may be operated bydetermining the air volume of each ventilation fan based on theinformation obtained by the total ventilation air volume decision means318 and the information about the air volumes and the number of theventilation fans installed in the same building. By doing so, even ifthe ventilation fans having respective sensors must increase the airvolume for a given period of time in tandem with sensor signals, theventilation fans can be controlled to increase or decrease therespective air volumes without any subordinate-superior relationshipamong the ventilation fans, thereby making it possible to optimallymaintain the air volume required for the whole building.

As in the ventilation system according to the sixth embodiment, the ideaof controlling the air volume of each ventilation fan by obtaining themutual air volume information among a plurality of ventilation fans toobtain the total ventilation air volume required for the wholeventilation system is applicable to the ventilation fan according to thefirst embodiment referred to above.

By way of example, as shown in a block diagram indicating a controlconfiguration of a plurality of ventilation fans of a ventilation systemof FIG. 30, a communication module 336 may be replaceably mounted on abody unit 51 of each ventilation fan to allow transmission and receptionof the air volume information among the plurality of ventilation fans.

If such a communication module 336 is configured as a common modulewith, for example, the sensor module 36 and if one of the ventilationfans requires the communication module 336, the sensor module 36 can bereplaced with the communication module 336. The communication module 336is provided with a floor area-setting portion 311, an informationtransmitting portion 316, an information receiving portion 317, a modulecontroller 330 for controlling these components, and a connector 338 tobe connected to a connector 16 b of a module mount 37.

A combination of the sensor module 36 having an indoor environmentdetecting sensor required for an indoor environment and thecommunication module 336 may be mounted on the body unit 51 to make itpossible to obtain the effects produced by the ventilation systemaccording to the sixth embodiment.

As described above, according to the fifth or sixth embodiment, becausethe ventilation fans create a network to provide an optimum air volumerequired for a building, the ventilation fans can be used in offices,shops and the like as well as in homes.

Any combination of the various embodiments referred to above can producerespective effects.

Although the present invention has been fully described by way ofpreferred embodiments with reference to the accompanying drawings, it isto be noted here that various changes and modifications will be apparentto those skilled in the art. Therefore, unless such changes andmodifications otherwise depart from the scope of the present inventionas set forth in the appended claims, they should be construed as beingincluded therein.

1. A ventilation fan comprising: a body unit including; a body casehaving an indoor air suction opening and an indoor air discharge openingboth defined therein, the body case configured to be located on or abovea ceiling board; a fan disposed in the body case; and a fan controlleroperable to control an air volume of the fan; a decorative board whichis removably mounted on the body unit so as to cover the indoor airsuction opening from a lower surface of the ceiling board; a sensormodule including; an indoor environment detecting sensor; and a modulecontroller operable to control a detecting operation of the indoorenvironment detecting sensor; wherein the body unit has a module mounton which the sensor module is mounted and another sensor module can bemounted in place of the sensor module, the module mount comprising oneor more electrical connectors for electrically connecting with thesensor module, and the module mount being electrically connected to thefan controller, and the decorative board has a ventilation hole, theventilation hole is a hole for communicating the indoor air suctionopening in the body case with an indoor space to allow indoor air to beintroduced into the body case by passing through the decorative boardand the indoor air suction opening, and the module controller outputsdetection information obtained based on a detection result of the indoorenvironment detecting sensor to the fan controller, which controls theair volume of the fan based on the detection information inputtedthereto.
 2. The ventilation fan according to claim 1, wherein thedecorative board has a mounting portion, and wherein the sensor moduleis removably mounted to the mounting portion.
 3. The ventilation fanaccording to claim 1, wherein the sensor module is mounted on a cornerportion of the decorative board.
 4. The ventilation fan according toclaim 1, wherein the module controller outputs identificationinformation of the indoor environment detecting sensor to the fancontroller, which controls the air volume of the fan based on theidentification information and the detection information inputtedthereto.
 5. The ventilation fan according to claim 1, wherein aplurality of sensor modules can be simultaneously mounted on the modulemount and the fan controller has an arithmetic section to calculate theair volume of the fan based on different detection information inputtedfrom the plurality of sensor modules using an algorism set in advance.6. The ventilation fan according to claim 1, wherein the modulecontroller determines air volume information of the fan based on a kindor the detection result of the indoor environment detecting sensor andoutputs the air volume information determined as the detectioninformation to the fan controller.
 7. The ventilation fan according toclaim 1, wherein a connecting portion of the sensor module to beconnected to the module mount has a common shape with a connectingportion of another sensor module.
 8. The ventilation fan according toclaim 1, wherein the sensor module comprises at least one of a humanbody detecting sensor, a temperature sensor, a humidity sensor, anillumination sensor, a carbon monoxide sensor and a carbon dioxidesensor as the indoor environment detecting sensor.
 9. A ventilationsystem operable to hold a ventilation air volume constant in a building,comprising: at least two ventilation fans according to claim 1 installedin the same building; and each ventilation fan comprising; aninformation transmitting portion operable to transmit its own air volumeinformation determined based on detection information inputted from asensor module mounted thereon to other ventilation fans; an informationreceiving portion operable to receive information from the otherventilation fans; and an air volume decision means operable to compare atotal air volume of the air volume information of its own fan and theair volume information of the other ventilation fans received by theinformation receiving portion with a total ventilation air volumeinformation in the building set in advance to determine the air volumeof its own fan so as to maintain the total ventilation air volume. 10.The ventilation system according to claim 9, wherein each ventilationfan comprises a communication module having the information transmittingportion and the information receiving portion and being mounted on themodule mount.
 11. A ventilation system comprising: a body unit for aventilation fan, the body unit including; a body case having an indoorair suction opening and an indoor air discharge opening both definedtherein, the body case configured to be located on or above a ceilingboard; a fan disposed in the body case; and a fan controller operable tocontrol an air volume of the fan; first and second decorative boards,each of which is configured to be removably mounted on the body unit soas to cover the indoor air suction opening from a lower surface of theceiling board; a sensor module including; an indoor environmentdetecting sensor; and a module controller operable to control adetecting operation of the indoor environment detecting sensor; whereinthe body unit has a module mount on which the sensor module is mountedand another sensor module can be mounted in place of the sensor module,the module mount comprising one or more electrical connectors forelectrically connecting with the sensor module, and the module mountbeing electrically connected to the fan controller, and the first andsecond decorative board each have a ventilation hole, the ventilationhole is a hole for communicating the indoor air suction opening in thebody case with an indoor space to allow indoor air to be introduced intothe body case by passing through the decorative board and the indoor airsuction opening, and the module controller outputs detection informationobtained based on a detection result of the indoor environment detectingsensor to the fan controller, which controls the air volume of the fanbased on the detection information inputted thereto, the mountingportion of the second decorative board having a different shape from themounting portion of the first decorative board and in which anothersensor module is configured to be mounted, and the first decorativeboard is replaceable with the second decorative board.